The present invention relates to systems used to deliver a prosthetic valve to a heart. More specifically, the present invention is directed to an improved delivery system for delivery of a prosthetic valve to a human heart.
Catheters for prosthetic heart valve implantation are known in the art and have been commonly used to reach locations inside the body that are not readily accessible by surgery or where access without surgery is desirable. Numerous transcatheter techniques are known in the art, including techniques which are percutaneous, trans-arterial, trans-venous, trans-cardiac, trans-atrial, trans-ventricular, and/or trans-apical. A key factor in such transcatheter heart valve deployment is properly positioning the prosthetic implant, e.g., accurately positioning a prosthetic heart valve within the native heart valve annulus.
Over the years, a variety of techniques have been proposed and/or used for facilitating proper positioning of catheters. For example, current transcatheter valve implantation systems, such as the Edwards SAPIEN™ Transcatheter Heart Valve, use fluoroscopy and/or echography to properly position the valve within the native valve annulus prior to deployment. Such imaging modalities involve extensive and complicated equipment, and may also have limitations in their accuracy in some circumstances. Improvements may be desired which, when compared to known techniques, may provide improved accuracy, reduced cost/complexity, and/or backup positioning (when used in combination with known techniques).
Prior art methods also include modifications to the implant itself. For example, some transcatheter valve implantation systems employ retractable metal positioners that extend from the valve frame. For example, U.S. Pat. Nos. 7,201,772 and 7,399,315, as well as US Patent Publication No. 2008/0071362, disclose the use of positioners which are an integral component of the prosthetic heart valve frame. The positioners add extra material to the prosthetic heart valve. Also, upon deployment of the prosthetic heart valve in the patient, the positioners remained in the patient.
Another approach includes the filling (via injection, etc.) of a portion of the prosthetic implant itself with a radiographic contrast solution. After the surgeon or other user has properly positioned and deployed the implant, the radiographic contrast solution is pumped out and replaced with a hardening agent which increases the stiffness of the implant in order to aid in retaining the implant at the desired position. Such a technique is relatively complex.
Although a variety of prosthetic valve positioning methods and systems have been proposed over the years, each of the existing methods and systems has shortcomings. Additionally, improved methods and systems may be used in combination with previously-known methods in order to achieve improved accuracy and/or reliability. Accordingly, an urgent need exists for an improved valve positioning method and system which is versatile, reliable, and easy to use. The present invention addresses this need.